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Effects of photoperiod, time of year, temperature, and an insect growth regulator (fenoxycarb) on ovarian development rate in overwintering pear psylla, Cacopsylla pyricola (Foerster), were determined. Winterform pear psylla were collected from the field at intervals between October and February, and reared at 20 °C and one of three treatments: short-day photoperiod, long-day photoperiod, or short-day photoperiod + fenoxycarb. Insects were then dissected at intervals to score ovarian development. Baseline scores (i.e., ovarian development in the field on date of collection) increased very slowly between October and February. By mid-February, only about 20% of insects in the field were categorized as having postdiapause status based upon ovarian development. In the laboratory, time required for insects to reach postdiapause status decreased between the October and February collection dates. Number of days necessary for 50% of the long-day insects to reach postdiapause status was approximately 2 weeks in October, 6 days in December, and < 2 days in February. Short-day insects also required fewer than 2 days in February, but required > 2 weeks in the October and December samples. Our results suggested that insects collected in January and February had completed diapause but that ovarian development was subsequently prevented in the field by low temperatures. Fenoxycarb caused rapid ovarian development even in October-collected insects; rate of development was only slightly more rapid in the February-treated psylla.

The influence of male and female body size on copulation duration and probability of insemination was determined for Anthocoris whitei Reuter allowed to mate at two temperatures. Copulation duration decreased significantly with increasing male length or increasing relative size (male length divided by female length). Female length had no effect on copulation duration. We interrupted copulation at 20 or 40 min at both 25 and 15 °C to determine the interacting effects of male size, temperature, and copulation duration on probability of insemination. Insemination probabilities increased with increasing male size, increasing temperature, and increased duration of copulation. Large males were more successful than small males at inseminating females at cool temperatures and for severely shortened copulations. Results are consistent with the hypothesis that males of this species experience physical difficulties either in achieving intromission or in forcing sperm through the aedeagus, and that larger body size in males lessens these difficulties.

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